The present invention relates to a cutter for cutting, in stages, irradiated bundles of nuclear fuel rods, especially from pressurized-water or boiling-water reactors. The cutter includes a feed channel with which is associated transverse and longitudinal feed devices for the rod bundle. The cutter also includes a cutter housing arranged at the mouth of the channel and provided with a cutter carriage which can be moved at right angles to the feed channel and which is provided with a cutting blade; a fixed counterblade which cooperates with the cutting blade; and a rod bundle clamping mechanism which is located ahead of the cutting plane and is provided with two alternately actuatable clamping jaws. The cutter carriage, along with the cutting blade, the counter-blade, and the two clamping jaws can be removed and replaced. Furthermore, the transporting, clamping, and cutting devices are respectively provided with their own drive unit.
With such cutters, not only the cutting tools, but also all of the other parts which are located within the feed device and the cutter housing, but which do not take part in the cutting procedure, are subjected to considerable wear and therefore require frequent repair or replacement. Of course, the cutting tools are of greater significance, since if during cutting deformations in the form of compressed tube openings result, these deformations have a negative affect on the subsequent chemical separating process due to the thereby retarded acid attack.
German Offenlegungsschrift No. 28 57 114 discloses a cutter of the aforementioned general type which is provided with an exchangeable cutter head in which are located not only two clamping jaws of a clamping device, which clamping jaws can be moved back and forth, but also a cutter carriage which can be moved back and forth and which is provided with a blade and an abutment for supporting the fuel elements which are to be cut up. A drawback with this heretofore known cutter is that in order to replace individual parts, the entire cutter head must first be removed from the cutter. This removal of the cutter head additionally takes a lot of time because the movable parts in the cutter head are connected by means of driving and connecting rods with associated hydraulic drives which are located outside of the cutter, and these connections must be disconnected before the cutter head can be lifted out of the cutter for replacement. This loss of time is also required for installation of the cutter head.
To avoid this drawback it is already known from German Patent 29 44 197 to construct a cutter unit in two parts, with a blade and its drive devices being arranged in the cutter unit, and with the blade being guided in a two-part cutter sleeve. After the upper part of the cutter unit is removed, the interior of the lower part of the cutter unit is more accessible, and the installation and removal of a component located in the lower part of the cutter unit is facilitated.This is not true, however, for the cutter blade, the lower surface and the two side surfaces of which are slidingly movable in the guide part of the blade, because the cutter blade is covered by a blade plate which is mounted on the guide part of the blade; this cutter plate impedes access to the blade and must be removed in order to replace or repair the cutter blade.
It is an object of the present invention to construct a cutter of the aforementioned general type for cutting, in stages, irradiated bundles of nuclear fuel rods in such a way that all of the structural components which take part in the gradual feed and the cyclic cutting, and which are either movable or fixed, can be exposed and replaced or exchanged in a simple manner.